Half of the donor countries used money from outside their aid budgets to cover these costs.

Syrian children receive humanitarian aid in the settlement of AlkinCredit:
Barcroft Media

Many EU countries, however, have increased aid given to themselves in order to handle the refugee crisis.

Countries most affected by the refugee crisis, such as Greece, Sweden and Germany, saw their development budgets soar over the last year.

While Greece's ODA surged by 38.7 per cent over the year, Sweden's increased by 36.8 and Germany by 25.9 per cent between 2014 and 2015. Growing in-donor refugee costs were at least partly responsible for these increases, according to the OECD.

The largest donor countries by volume were the United States, the United Kingdom, Germany, Japan and France. These five countries gave a total of $86bn in 2015.

In 2015, ODA as a share of gross national income was 0.3 per cent, reaching the same level as 2013 when aid reached a record high of $135.1bn.

The authors of the report said: "Most of the increase in 2015 was due to higher expenditures for in-donor refugee costs as a result of the surge of asylum seekers.

"However, if these cost are excluded, net ODA still continued to grow by 1.7 per cent in real terms. Despite the recession in several DAC member countries which has led to cuts in aid budgets, overall levels of ODA continue to grow; since 2000, net ODA has increased by 83 per cent in real terms."